So, I hope there is no such thing as a stupid question in this forum....

I pull up to the pump yesterday with my 16 yr old son. Being a good dad I told him to get out and pump (22 degrees and raining), gave him my card and told him to fill it up with the "high test" (yea old school) because I have the GM Stage kit installed. Long story short I got the e me the card and recpt back. Holy Sh8t... $125 dollars later... I realized there was a 100 octane pump.

So the questions...
1. Will I see a difference in my cars performance with 100 vs 93?
2. How about mixing 100 and 93
3. Why would you use 100

 

Yes good performance with the 100. 100 is used mostly for racing gas. I used to put it in the harley and hear the exhaust change to a nice tone.

 

One benefit you may see in some engines is more power because of the ability of the gasoline to more fully evaporate in to a gas. Higher octane fuels vaporize quicker and more complete. This would contribute to a more complete burning of the fuel charge.

I am going to guess that any performance difference may only be realized in very hot weather because pre-detonation is more common in hot weather. I may be wrong because I do not have any experience with a direct injected engine.

 

even with a performance engine, youre really not going to see a difference in performance in "every day driving" now if youre a lead foot, sure you might feel a lil extra pressure in the seat, might hear a lil different exhaust noise, but to be honest, its not worth the extra 80-90 bucks (that is if your 93 octane is roughly 2 bucks a galon) per tank... and the racing fuel is like 7-8 bucks a galon (again if you have a 16 galon tank)

in "mixing" 100 and 93... not recomended, the different fuels will burn differently thus you may experience "spurts" in the engine performance

as for why to use higher octane fuel, well there are several reasons:
less chance of detonation at high RPM's- high octane fuel is used in high compression engines that are designed to run at very fast rpms (5-8K RPM) that have very advanced timing, this is so the engine is usually running at its optimal HP and torque band, like TomsHHR said- its racing gas so its specificly designed for people that crank on their engines

 

You will see no benefit to race gas in an engine that's not specifically tuned for it. In fact fuel economy will decline by a small amount.

Octane defines the resistance to detonation. It has nothing to do with the amount of energy available in a given quantity of fuel.

Most forced induction engines are detonation limited. That is, the engine will go into destructive detonation before timing can be advanced to place peak cylinder pressure at 14-16* ATDC, which is a non-negotiable piston position. Under these circumstances, higher octane fuel will allow a spark advance setting that is more efficient, producing more torque. Unless you're in a situation where the ECM is constantly pulling spark due to knock retard, there will be no increase of power with increased octane.

 

Siphon that 100 octane gas out of your car NOW.

Put it in your lawn mower.

Start the lawn mower and watch it cut your grass all by itself in half the time...and all the neighbors lawns too! You'll love it!!!

If you have snow, put it in the snow blower. It will blow the snow 14 blocks away.

Yeah...I have fun with 100 Octane Gas.

Oh...by the way...what Mister Mike said above...yeah, I would go with that.

Peace!

 

100 octane gas is nose candy!!! Smells sweet like candy. As for performance, unless you have a custom tune, probably not much difference.

 

The differance will be your wallet is a lot lighter.......

 

He said it was $125!
Can you imagine that, tell your kid to put the "high test" in, and have him hand you a receipt for....$125!?!? Not the kids fault.

 

I put some Sunoco 100 octane unleaded in my GTO after a new engine went in, to offset the deterioration of octane from the existing fuel sitting for so long. (draining the tank was off the table) You could smell the Xylene from 10 feet away. Don't splash this stuff on your paint, whatever you do.